1. Field of the Invention
This invention relates generally to dynamoelectric devices. More specifically, this invention pertains to an end turn phase insulator comprising a tab configured and adapted to prevent stator lead wires from migrating into a bore of a stator and to prevent the lead wires from migrating radially outward beyond one of the windings of the stator.
2. General Background Technology
Most dynamoelectric devices comprise lead wires extending from at least one axial end of the stator. Such lead wires are typically subjected to motion relative to the stator caused by the inertia of such leads interacting with vibrations or movement of the dynamoelectric devices. Over time, this can cause the lead wires to migrate relative to the stator. Due to the proximity of typical lead wires to the rotors of dynamoelectric devices, a common failure of dynamoelectric devices results from the lead wires migrating to the point where they make contact with the rotor or other moving parts in the stator bore, which can cause the device to short.
To reduce the occurrence of lead wire migration, prior art dynamoelectric devices often include some means of restraining or supporting the lead wires relative to the stator. For example, zip ties have been used to prevent or limit lead wire migration. However, zip ties are susceptible to breaking down in certain environments, such as when the dynamoelectric device is exposed to refrigerants or oils. As another example, U.S. Pat. No. 4,328,438 discloses a dynamoelectric device wherein a flap (27) is looped around an end turn and wrapped over the lead wires. Lacing is then used to sandwich the lead wires between the flap and the end turns of the windings of the stator. Although such a flap reduces the occurrence of lead wire migration, it does not have any positive stop means for limiting migration of the lead wires radially inwardly to the inner radial surface of the innermost winding. Additionally, such a flap is configured as part of a holder member that is separate from other components of the dynamoelectric device. Such separate components add to the cost, complicate the assembly process of dynamometric devices, and permit assembly without the component installed.
Another problem associated with lead wires is caused by the lead wires being positioned too close to the outer diameter of the stator windings. This creates a potential for interference with the housing shells or other components during the assembly or installation of the dynamoelectric devices.